Rheostat.



T. RHODUS.

RHEOSTAT.

APfLlcATloN FILED MAR.24.1915.

Patent-ed Nov. 2, 1915.

UNITED sTATEs PATENT onricn.

THOMAS RHODUS, 0F CHICAGO, ILLINOIS.

RHEOSTAT.

To aZZ whom it may concern:

Be it known that I, THOMAS RHoDUs, a citizen of the United States of America, and a resident'of Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Rheostats, of which the following is a specification.

This invention relates more especially to that type of rheostats forming the subject matter of my prior application for patent, Serial No. 879,009, and has for its object to provide a simple and efficient structural formation and association of, the parts which carry the adjustable contact element or member, and by means of which said adjustable contact element is yieldingly held in contact with the annular stationary'resistance element or member of the rheostat in an eiicient manner, all as will hereinafter more fully appear.

In the accompanying drawings: Figure 1, is a'sectional plan of a rheostat having the present improvement applied. Fig. 2, is a detail perspective view of the adjustable contact member and 'its accessories. Figs. 3 and 4, are detail perspective views illustrating modified formsof the resilient carying means of the adjustable contact mem- -Similar reference numerals indicate like parts in the several views. I

Referring to the drawings, 1 designates a suitable supporting base having the usual insulating slab or web 2, upon which are supported the stationary resistance element and its accessories, hereinafter described. v

8, designates the inclosing shell of the rheostat of any usual and suitable construction.

4 designates the resistance element or member of the rheostat, formed by a series of fiat and open spiral windings of resistance wire, wound upon an insulating core ordinarily of an open ring shape the over-lapping ends of which are secured to a supporting bracket 5, on the insulating slabv or web 2, aforesaid, as set forth in detail in my prior Patent No. 1,053,219, of February 18, 1915, and said core and itsl reslstance winding have a concentric relation to the center of'the rheostat as illustrated in Fi .1.

6g designates a centrally arranged hub on the insulating slab or base 2 aforesaid, in

Specification of Letters Patent.

Patented Nov. 2, 1915.

Application led March 24, 1915. Serial No. 16,546.

which the handled operating shaft 7 of the rheostat is revolubly mounted.

8. designates a carrying head or yoke in which is journaled a roller'or drum 9 having rolling contact with the inner surface of the stationary resistance element 4, and constituting the movable contact of the rheos tat. Said construction admits of the formation of a roller or drum of ample length to afford a corresponding extent of electrical contact with one or more individual spirally Wound strands of the wire of the resistance element 4, aforesaid.

The carrying head 8 is operatively connected to the revoluble shaft 7 aforesaid, so as to move in unison therewith and in a circular path upon the interior of the stationary resistance element 4, aforesaid, and in the present improvement, is resiliently held to such bearing contact by the detail construction of parts now to be described.

10 designates a radial bar or rod Xedly attached to the revoluble shaft 7 aforesaid, with its outer end having sliding engagement in a guide sleeve 11 on the aforesaid carrying head or yoke 8. Turning movement of said head or yoke 8 upon said bar orl rod 10 is prevented by a transverse pin and elongated slot formation 12 of the respective parts, and the resilient outward tendency of said head or yoke 8 is attained by the outward stress of a spiral spring 13 encircling the bar or rod 10, as illustrated in Figs. 1 and 2.

In the modified construction illustrated in Fig. 3, the radially disposed rod or bar 10 is a fixture on the carrying head or yoke 8, and is slidingly mounted at its inner end in a transverse guide orifice inthe revoluble shaft 7. Turning movement of said head or yoke 8 and guide rod vor bar 10 is prevented by a radial bar or rod 14, fiXedly secured to the shaft 7 in spaced relation to the rod or bar 10 and h aving sliding engagement with guide pins 15, or like means, on the carrying head or yoke 8, aforesaid. With said modified construction, a substantially counterpart spring 13 to that heretofore described will be employed to resiliently force the head or yoke 8, outwardly.

In a modified construction illustrated in Fig. 4, the carrying head or yoke 8 is operatively connected to the revoluble shaft 7 in a direct manner by va resilient connecting arm or member 16, attached at its respective diate of its length. 17 and 18 designatel binding posts attached to an outer portion of the insulating slab or web 2, aforesaid,v

and having line connections respectively With the stationary resistance element i and With the movable contact element 9, as illustrated in Fig. 1.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is

In a rheostat, the combination of a curved Lisanne resistance element formed in the main of 15 a resistance wire Wound into an open series of convolntions, a rolling contact element having contact With the inner surface ofsaid resistance element, a centrally arranged revoluble shaft, a carrying head for said 20 rolling contact element, and means associated with said shaft and carrying head for holding said rolling Contact element in Working relation, substantially 'as set forth.

Signed at Chicago, illinois, this 22nd day 25 of March, 1915.

y uTnoivnis RHonns. 

